Gas insulation switchgear

ABSTRACT

A gas insulation switchgear having a lowered overall height is provided.  
     The height of the gas insulation switchgear can be lowered by constructing the gas insulation switchgear so as to comprise a breaker unit  13  horizontally arranged in the lower side and containing a conductor for one phase in a container; an actuator  41  arranged in the axial direction of the breaker unit  13 ; and a main bus isolator unit  4  horizontally arranged in both sides of a bus side connecting conductor  46  through the bus side connecting conductor  46  arranged vertically and connected to the breaker unit  13.

FIELD OF THE INVENTION

[0001] The present invention relates to a gas insulation switchgear and,more particularly a gas insulation switchgear suitable for small sizing.

BACKGROUND OF THE INVENTION

[0002] Gas insulation switchgears are widely installed in substationsand the like because they are good in insulating performance, suitablefor a small-sized machine, and safe. The gas insulation switchgear is asystem which comprises a plurality of enclosed containers, each of theenclosed containers contains a breaker, an isolator, a grounding switch,an instrumental current transformer and current conducting conductorsfor electrically connecting these components and is filled with aninsulation gas.

[0003] The insulator of such a gas switchgear is constructed so that amovable contact is detached from a main circuit by driving a mechanismportion and an insulation rod by an actuator arranged outside the tank.As described in the Transactions of 1997 National Meeting of theInstitute of Electrical Engineers of Japan, Paper No. 1584, pages382-383, there is a gas insulation switchgear in which a bus is disposedin the bottom, a pole gap is disposed above the bus, a driving portionis disposed above the pole gap, and a conductor in the same phase as amovable contact connected to an insulation rod is penetrated.

[0004] Further, there is a gas insulation switchgear, as disclosed inJapanese Patent Application Laid-Open No. 49-78850, in which athree-phase single-unit transformer capsule of a horizontal type isconnected to a three-phase single-unit breaker of a horizontal type, athree-phase single-unit connection capsule of a vertical type isconnected to the three-phase single-unit transformer capsule, andthree-phase single-unit buses are connected to the left-hand side andthe right-hand side of the connection capsule through a three-phasesingle-unit isolator.

[0005] In a case where the three-phase single-unit gas insulationswitchgear as described in the Transactions of 1997 National Meeting ofthe Institute of Electrical Engineers of Japan, Paper No. 1584, pages382-383 is used, and the main circuit is led out in the horizontaldirection from the bus isolator, the insulation spacers are horizontallyarranged in the isolator and accordingly there is a problem in thatmetallic extraneous objects are accumulated on the insulation spacers toreduce the reliability. Further, as described in the Transactions of1997 National Meeting of the Institute of Electrical Engineers of Japan,Paper No. 1584, page 392, there is a problem in that an installationheight becomes high in the structure of a phase separation type isolatorbecause three conductors are vertically arranged inside an isolator tankand the main bus containers should be vertically installed in order toconstruct the phase separation type isolator though the main circuitscan be led out in the horizontal direction.

[0006] In the gas insulation switchgear disclosed in Japanese PatentApplication Laid-Open No. 49-78850, the height of the gas insulationswitchgear can not lowered because the breakers, the transformercapsules and the isolators are constructed in the three-phasesingle-unit type, and consequently the outer diameters of the breaker,the transformer capsule and the isolator become larger.

[0007] A first object of the present invention is to provide a gasinsulation switchgear in which the height of the whole system islowered.

[0008] A second object of the present invention is to provide a gasinsulation switchgear which is suitable for arranging the insulationspacers in the vertical direction.

[0009] A third object of the present invention is to provide a gasinsulation switchgear which is suitable for transporting the gasinsulation switchgear composing the transmission line in a unit.

[0010] A fourth object of the present invention is to provide a gasinsulation switchgear which is suitable for performing inspection.

SUMMARY OF THE INVENTION

[0011] The objects described above can be attained by a gas insulationswitchgear in accordance with the present invention comprising a breakerunit horizontally arranged and containing a conductor for one phase in acontainer; a bus side connecting conductor vertically arranged andconnected to the breaker; three-phase single-unit type main bus unitsarranged in both sides of the bus side connecting conductor and in anaxial direction of said breaker unit; and a line side connectingconductor connected to the breaker unit.

[0012] Further, a gas insulation switchgear in accordance with thepresent invention comprises a breaker unit horizontally arranged andcontaining a conductor for one phase in a container; a bus sideconnecting conductor vertically arranged and connected to the breaker; athree-phase single-unit type main bus A connected to the bus sideconnecting conductor; a line side connecting conductor connected to thebreaker unit; and a three-phase single-unit type main bus B connected tothe line side connecting conductor, wherein a connecting port to themain bus A of the bus side connecting conductor and a connecting port tothe main bus B of the line side connecting conductor are arranged in thesame direction.

[0013] Further, a gas insulation switchgear in accordance with thepresent invention comprises a breaker unit having a bus section line anda bus communication line horizontally arranged, containing a conductorfor one phase in a container; a bus side connecting conductor verticallyarranged and connected to the breaker; three-phase single-unit type mainbus units arranged in both sides of the bus side connecting conductorand in an axial direction of the breaker unit; and a line sideconnecting conductor connected to the breaker units.

[0014] Further, in a substation comprising a transmission line, a buscommunication line, a bus section line and a transformer line, a gasinsulation switchgear in accordance with the present invention has avoltage transformer unit in the bus section line.

[0015] Further, a gas insulation switchgear in accordance with thepresent invention comprises a breaker unit having a bus section linehorizontally arranged, containing a conductor for one phase in acontainer; a bus side connecting conductor vertically arranged andconnected to the breaker; three-phase single-unit type main bus unitsarranged in both sides of the bus side connecting conductor and in anaxial direction of said breaker unit; a line side connecting conductorconnected to the breaker units; and a voltage transformer connected toan end portion of the main bus.

[0016] Further, in the gas insulation switchgear in accordance with thepresent invention, the line side conductor has an isolator unit, and thebreaker unit and the isolator unit are mounted on a base, and a portionbetween the breaker unit and the bus side connecting conductor and aportion between the breaker unit and the isolator unit are soconstructed as to be separable.

[0017] Further, in the gas insulation switchgear in accordance with thepresent invention, a second base is arranged below the base describedabove.

[0018] Further, a gas insulation switchgear in accordance with thepresent invention comprises a breaker unit horizontally arranged andcontaining a conductor for one phase in a container; a bus sideconnecting conductor vertically arranged and connected to the breaker;three-phase single-unit type main bus units arranged in both sides ofthe bus side connecting conductor and in an axial direction of thebreaker unit; and a line side connecting conductor connected to thebreaker unit, the breaker unit and the isolator unit being mounted on abase, a portion between the breaker unit and the bus side connectingconductor and a portion between the breaker unit and the line sideconnecting conductor being so constructed as to be separable, whereinthe gas insulation switchgear is transported as a unit when the gasinsulation switchgear is transported, and the gas insulation switchgearis mounted on a second base.

[0019] Further, in the gas insulation switchgear in accordance with thepresent invention, when the breaker unit is disassembled, the breakerunit is dismounted by supporting the main bus unit with the othersupport column, and detaching the portion between the breaker unit andthe bus side connecting conductor and the portion between the breakerunit and the line side connecting conductor after removing the secondbase.

[0020] Further, a gas insulation switchgear in accordance with thepresent invention comprises a breaker unit horizontally arranged; a busside connecting conductor vertically arranged and connected to thebreaker; a current transformer unit arranged below the bus sideconnecting conductor; three-phase single-unit type main bus unitsarranged in both sides of the bus side connecting conductor and in anaxial direction of the breaker unit; and a line side connectingconductor connected to the breaker unit.

[0021] Further, in the gas insulation switchgear in accordance with thepresent invention, a current transformer unit is connected to thebreaker unit, and the breaker unit, the bus side connecting conductorand the current transformer are so constructed as to have a common gassection.

[0022] Further, in the insulation switchgear in accordance with thepresent invention, a current transformer unit is connected to thebreaker unit, and the current transformer is so constructed to have atank different from a tank of the breaker unit.

[0023] Further, a gas insulation switchgear in accordance with thepresent invention comprises a breaker unit horizontally arranged; a busside connecting conductor vertically arranged and connected to thebreaker; three-phase single-unit type main bus units arranged in bothsides of the bus side connecting conductor and in an axial direction ofthe breaker unit; and a line side connecting conductor connected to thebreaker unit, wherein the line side connecting conductor is connected toa line side component through a current transformer arranged verticallyand an extendable joint.

[0024] Further, in the gas insulation switchgear in accordance with thepresent invention, the main conductors for three phases are horizontallyor vertically arranged in a row.

[0025] Further, a gas insulation switchgear in accordance with thepresent invention comprises a breaker unit horizontally arranged; a busside connecting conductor vertically arranged and connected to thebreaker; three-phase single-unit type main bus units arranged in bothsides of the bus side connecting conductor and in an axial direction ofthe breaker unit; and a line side connecting conductor connected to thebreaker unit, wherein an insulation spacer is horizontally arrangedbetween the line side connecting conductor and the breaker unit, and agrounding device is arranged in the main bus unit.

[0026] Further, a gas insulation switchgear in accordance with thepresent invention comprises a breaker unit horizontally arranged; a busside connecting conductor vertically arranged and connected to thebreaker; three-phase single-unit type main bus units arranged in bothsides of the bus side connecting conductor and in an axial direction ofthe breaker unit; and a line side connecting conductor connected to thebreaker unit, wherein the line side connecting conductor is connected toa breaker side grounding device, an isolator and a line side isolatorwhich are contained in a container vertically arranged.

BRIEF DESCRIPTION OF DRAWINGS

[0027]FIG. 1 is a plan view showing an embodiment of a gas insulationswitchgear in accordance with the present invention which is installedat a substation.

[0028]FIG. 2 is a side view showing the gas insulation switchgear beingtaken on the plane of the line A-A of FIG. 1.

[0029]FIG. 3 is a side view showing the gas insulation switchgear beingtaken on the plane of the line B-B of FIG. 1.

[0030]FIG. 4 is a side view showing the gas insulation switchgear beingtaken on the plane of the line C-C of FIG. 1.

[0031]FIG. 5 is a plan view showing an embodiment of a gas insulationswitchgear in accordance with the present invention.

[0032]FIG. 6 is a front view showing the gas insulation switchgear beingtaken on the plane of the line D-D of FIG. 5.

[0033]FIG. 7 is a longitudinal sectional view showing a gas insulationswitchgear used in an electric power transmission line.

[0034]FIG. 8 is a longitudinal sectional view showing another embodimentdifferent from the gas insulation switchgear of FIG. 7.

[0035]FIG. 9 is a transverse sectional view showing a bus line isolator.

[0036]FIG. 10 is a cross-sectional view showing the bus line isolatorbeing taken on the plane of the line E-E of FIG. 9.

[0037]FIG. 11 is a cross-sectional view showing the bus line isolatorbeing taken on the plane of the line F-F of FIG. 9.

[0038]FIG. 12 is a cross-sectional view showing the bus line isolatorbeing taken on the plane of the line G-G of FIG. 9.

[0039]FIG. 13 is a cross-sectional view showing the bus line isolatorbeing taken on the plane of the line H-H of FIG. 9.

[0040]FIG. 14 is a cross-sectional view showing the bus line isolatorbeing taken on the plane of the line I-I of FIG. 9.

[0041]FIG. 15 is a transverse partially sectional view showing a gasinsulation switchgear.

[0042]FIG. 16 is a longitudinal partially sectional view showing a gasinsulation switchgear.

[0043]FIG. 17 is an enlarged longitudinal sectional view showing a mainbus isolator.

[0044]FIG. 18 is an enlarged side view showing an operating mechanismportion.

[0045]FIG. 19 is an enlarged longitudinal sectional view showing acurrent transformer unit.

[0046]FIG. 20 is an enlarged longitudinal sectional view showing acurrent transformer unit.

[0047]FIG. 21 is an enlarged longitudinal partially sectional viewshowing an isolator unit.

[0048]FIG. 22 is an enlarged plan view showing an operating mechanismportion of the isolator.

[0049]FIG. 23 is an enlarged longitudinal partially sectional viewshowing the operating mechanism portion of the isolator.

[0050]FIG. 24 is a longitudinal sectional view showing a gas insulationswitchgear for bus line communication.

[0051]FIG. 25 is a longitudinal sectional view showing a gas insulationswitchgear for transformer circuit.

[0052]FIG. 26 is a front view showing another embodiment of a gasinsulation switchgear used for an electric power transmission line inaccordance with the present invention.

[0053]FIG. 27 is a longitudinal sectional view showing the structure ofanother embodiment of a gas insulation switchgear in accordance with thepresent invention when the main buses are arranged below.

[0054]FIG. 28 is a longitudinal sectional view showing the structure ofanother embodiment of a gas insulation switchgear in accordance with thepresent invention when the main buses are arranged below.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0055] An embodiment of the present invention will be described below,referring to FIG. 1 to FIG. 25. FIG. 1 is a plan view showing anembodiment of a gas insulation switchgear in accordance with the presentinvention which is installed at a substation; FIG. 2 is a side viewshowing the gas insulation switchgear being taken on the plane of theline A-A of FIG. 1; FIG. 3 is a side view showing the gas insulationswitchgear being taken on the plane of the line B-B of FIG. 1; FIG. 4 isa side view showing the gas insulation switchgear being taken on theplane of the line C-C of FIG. 1; FIG. 5 is a plan view showing the gasinsulation switchgear shown in FIG. 2; FIG. 6 is a front view showingthe gas insulation switchgear being taken on the plane of the line D-Dof FIG. 5; FIG. 7 is a longitudinal sectional view showing the gasinsulation switchgear shown in FIG. 2 which is used in an electric powertransmission line; FIG. 8 is a longitudinal sectional view showinganother embodiment different from the gas insulation switchgear of FIG.7; FIG. 9 is a transverse sectional view showing a bus line isolator;FIG. 10 is a cross-sectional view showing the bus line isolator beingtaken on the plane of the line E-E of FIG. 9; FIG. 11 is across-sectional view showing the bus line isolator being taken on theplane of the line F-F of FIG. 9; FIG. 12 is a cross-sectional viewshowing the bus line isolator being taken on the plane of the line G-Gof FIG. 9; FIG. 13 is a cross-sectional view showing the bus lineisolator being taken on the plane of the line H-H of FIG. 9; FIG. 14 isa cross-sectional view showing the bus line isolator being taken on theplane of the line I-I of FIG. 9; FIG. 15 is a transverse partiallysectional view showing the gas insulation switchgear being taken on theplane of the line J-J of FIG. 8; FIG. 16 is an enlarged longitudinalpartially sectional view showing the gas insulation switchgear shown inFIG. 15; FIG. 17 is an enlarged longitudinal sectional view showing themain bus isolator shown in FIG. 12; FIG. 18 is an enlarged side viewshowing the operating mechanism portion being taken on the plane of theline K-K of FIG. 9; FIG. 19 is an enlarged longitudinal sectional viewshowing the current transformer unit shown in FIG. 17; FIG. 20 is anenlarged longitudinal sectional view showing a current transformer unit;FIG. 21 is an enlarged longitudinal partially sectional view showing theisolator unit shown in FIG. 7; FIG. 22 is an enlarged plan view showingthe operating mechanism portion of the isolator being taken on the planeof the line L-L of FIG. 21; FIG. 23 is an enlarged longitudinalpartially sectional view showing the operating mechanism portion of theisolator being taken on the plane of the line M-M of FIG. 21; FIG. 24 isa longitudinal sectional view showing the gas insulation switchgear forbus line communication shown in FIG. 3; and FIG. 25 is a longitudinalsectional view showing the gas insulation switchgear for transformercircuit shown in FIG. 4.

[0056] A transmission line is connected to bushings 1 from a pyloninstalled in a substation. As shown in FIG. 1, in this embodiment, thetransmission lines 2 are four lines, and the transformer lines 3 are twolines. In regard to main buses 4, the two main buses of main buses A 4a, 4 d and main buses B 4 b, 4 c are arranged nearly in parallel to eachother. A bus communication line 5 a and a transformer line 3 a aresuccessively connected to the main buses 4 a, 4 b between thetransmission line 2 a and the transmission line 2 b, and the transformerline 3 a is connected to a transformer 7 a. Bus section lines 6 a, 6 bare arranged in the main buses 4 a, 4 b, 4 c, 4 d between thetransmission line 2 b and the transmission line 2 c. A transformer line3 b and a bus communication line 5 b are successively connected to themain buses 4 c, 4 d between the transmission line 2 c and thetransmission line 2 d, and the transformer line 3 b is connected to atransformer 7 b.

[0057] As shown in FIG. 2, a three-phase single-unit bus 8 is connectedbetween the bushing 1 and the transmission line 2. The bus 8 isseparated into each phase to be connected to the transmission line 2.The bus 8 is successively connected to a lightning arrester 9gas-sectioned, a voltage transformer unit 10 gas-sectioned, isolatorunits 11 a, 11 b gas-sectioned together with a grounding device, acurrent transformer unit 12, a breaker unit 13, a current transformerunit 14, and two main bus isolator units 15 a, 15 b arranged in a branchportion 250 from the main bus 4.

[0058] As shown in FIG. 3, the bus communication line 5 is constructedby successively connecting a main bus isolator unit 20, a groundingdevice unit 16, a current transformer 17, a breaker unit 18, a currenttransformer 19 and a main bus isolator unit 21 to the main bus 4 a, andthe main bus isolator unit 21 is connected to the main bus 4 b. Theseunits are arranged in a line, and the connecting ports are arranged inthe same direction.

[0059] As shown in FIG. 4, the transformer line 3 is constructed byconnecting main bus isolator units 25, 26 to the main buses 4 a, 4 b,respectively, and connecting the main bus isolator units 25, 26 to abranch portion 251, and successively connecting a current transformer27, a breaker unit 28, a current transformer 29, a grounding device unit30, a lighting arrester 31 and a bus 32 to the branch portion 251, andthe bus 32 is connected to a transformer 33.

[0060] The bus section lines 6 are arranged at a central side betweenthe main buses 4 a, 4 b and at a central side between two main buses 4b, 4 d, and constructed similarly to the bus communication line 5 shownin FIG. 3. The two buses 4 a, 4 c are connected with the bus sectionline 6 a, and the two buses 4 b, 4 d are connected with the bus sectionline 6 b. As shown in FIG. 1, Voltage transformers 22 a, 22 b arearranged at the other ends of the branching buses of the bus sectionlines 6 a, 6 b in the same horizontal level as the main bus 4 isarranged.

[0061] The voltage transformer units 22 a, 22 b are arranged at a levelnearly equal to the level of the main bus 4 in a direction perpendicularto the axes of the main buses 4 a, 4 b, 4 c, 4 d of the bus section line6. Therefore, a space between the transmission line 2 b and thetransmission line 2 c can be reduced, and the voltage transformer unitsdo not need to be arranged at positions other than the main buses 4 a, 4b, 4 c, 4 d, and accordingly the length of the main buses 4 a, 4 b, 4 c,4 d can be shortened. Further, since the gas insulation switchgear usingthe bus communication line in the bus section line, the commonality ofcomponents can be performed. Furthermore, by arranging the axis of thebus section line 18 in parallel to the main buses 4 a to 4 d, thedistance between the transmission lines 2 b and 2 c can be shortened.

[0062] The gas insulation switchgear comprising the transmission lines,the bus communication lines, the bus section lines and the transformerlines of two-line system as described above can be installed aninstallation area within about 13 m width and about 30 m length.

[0063] Gas insulation switchgears for three phases installed in parallelare constructed as shown in FIG. 5 and FIG. 6. Phase conductors of thethree-phase single-unit main buses 4 a, 4 b combining and containingthree-phase conductors positioned at vertexes of a triangle together ina container are connected to the main bus isolator units 15 a, 15 bthrough a branching A portion to form respective phase lines. The gasinsulation switchgears composing the three-phase lines may be arrangedin parallel so that the containers having a larger outer diameter outof, for example, the actuators or the breaker units are in contactingwith each other, or may be arranged in parallel so that the containersare closely spaced between them.

[0064] The construction of the gas insulation switchgear used in atransmission line will be described in detail below, referring to FIG. 7and FIG. 8. As shown in FIG. 7, a breaker unit 13 is horizontally placedin the lower side, and an actuator 41 for driving an movable contact ofthe breaker unit 13 is arranged in the left hand side of the breakerunit 13. A bus connecting conductor 46 is arranged above the breakerunit 13 through a current transformer unit 14 and a flange. The busconnecting conductor 46 and a conductor 46 a connected to the breakerunit 13 are electrically connected with each other by a tulip contactportion 203. There is no insulation spacer in the connecting portion ofthe breaker unit 13, the current transformer 14 and the bus connectingconductor 46. Thereby, it is possible to prevent extraneous objects fromattaching an insulation spacer even if the extraneous objects aregenerated by making and breaking operation of the grounding device 52.The bus connecting conductor 46 is formed in a cross-shape, andhorizontally fixed and supported by insulation spacers 47 a, 47 b. Thegrounding device 52 is connected to the upper portion of the busconnecting conductor 46 through a flange. Main bus isolators 15 a, 15 bare arranged in the both sides of the insulation spacers 47 a, 47 bfixing and supporting the bus connecting conductor 46, and actuators 42,43 for operating movable contacts provided in the main bus isolatorunits 15 a, 15 b are arranged outside the main bus isolator units 15 a,15 b. An operating axis of each of the isolators for three phases isarranged on the central axis of the container, and the electrode gapsare arranged at one ends and the operating mechanism portions arearranged at the other ends interposing the conductor disposed on thecentral axis of the container out of the main bus 4. Detachable supportcolumns 201, 202 are arranged between the main bus 4 and the breakerunit 13 and between the main bus isolator unit 15 b and the breaker unit13, respectively. Therefore, when the breaker unit is removed in theevent of failure of the breaker unit 13, the main buses 4 a, 4 b and themain bus isolator units 15 a, 15 b can be supported by replacing thesupport columns 201, 202 with columns long enough to support them fromthe installation surface.

[0065] As described above, the main bus isolator units are horizontallyarranged in parallel to each other without stacking in the verticaldirection to reduce the height of the gas insulation switchgear. Sincein the gas insulation switchgear in accordance with the presentinvention the individual phase lines are constructed from thethree-phase single-unit main buses 4 a, 4 b, the outer diameter of thebreaker unit per phase can be lessened and the outer diameter of themain isolator units can be also lessened. Therefore, the height of thegas insulation switchgear can be lowered. For example, the height of agas insulation switchgear of even 300 kV class can be lowered to below 2m 70 cm, and accordingly the gas insulation switchgear can betransported by a trailer in a unit. Therefore, it is possible to reducethe transportation cost. Further, since the insulation spacers 47 a, 47b can be vertically arranged, accumulation of metallic extraneousobjects in the surfaces of the insulation spacers 47 a, 47 b can beprevented, and accordingly the reliability of the insulation can beimproved. The grounding device 52 may be arranged in any one of the mainbuses 4 a, 4 b. In this case, an insulation spacer may be horizontallyarranged, and accordingly the breaker unit 13 can be made smaller in thesection size and advantageous in the protection and monitoring.

[0066] In the embodiment shown in FIG. 7, a current transformer unit 12is connected to the right-hand side of the breaker unit 13 through aflange. An isolator unit 11 of a vertical type in the line side isarranged in the current transformer unit 12 through an insulator spacer48. The grounding device 52, the current transformer 14, the breakerunit 13 and the current transformer 12 are arranged in gas sectionssectioned by the insulation spacers 47 a, 47 b, 48. By constructing insuch a feature, the insulation spacer 48 can be disposed at a positiondistant from the breaker portion as far as possible to reduce an effectin the event of failure current breaking of the breaker unit 13.Further, the breaking performance can be improved by increasing anamount of gas in the breaking portion. A projecting grounding device 45in the lower side of the main bus isolator unit 15 a is horizontallyarranged in the isolator unit 11 in the line side. A grounding device 44is also arranged in the right-hand side of the isolator unit 11 in theline side and on a line extended from the breaker unit 13. A fixedelectrode 121 and a movable electrode 122 composing the isolatingportion are arranged inside the breaker unit 11 as to be describedlater, and a flange 204 is arranged at the position of the bothelectrodes in the isolator container of the isolator unit. Further, avoltage transformer unit 10 is arranged in the right-hand side of theline-side isolator unit 11 through an insulation spacer 49 and connectedto the isolator unit 11 through a T-shaped conductor. A conductor 53extending downward is connected to a conductor 54 having a branchingportion through an insulation spacer 50. The upper portion of theconductor 54 is connected to a lightning arrester unit 9 of a verticaltype through an insulator spacer 51. As shown in FIG. 7 and FIG. 8, thetwo buses 4 a, 4 b are arranged between the end of the breaker unit 13and the end of the actuator 41, and accordingly the freedom in arrangingthe components in the line side can be attained.

[0067] The breaker unit 13 and the isolator unit 11 are mounted on thebase 205, and the voltage transformer 10 and the lightning arrester unit9 are mounted on the base 206. As shown in FIG. 2 and FIG. 3, I-shapesteel blocks are arranged under the bases 205, 206, and the bases 205,206 are supported by the I-shaped steel blocks 252. The I-shaped steelblock 252 has a height of 250 mm. As described above, the bus connectingconductor 46 and the conductor 46a are electrically connected to eachother with tulip contact, and the flange 204 is arranged in the isolatorunit 11. Therefore, the breaker unit 13 and the fixed electrode 121 sideof the isolator unit 11 can be detached off from each other by removingthe flange after discharging the gas. Accordingly, when the breaker unit13 needs to be removed, the breaker unit 13 can be detached by oncejacking up the base 205 to remove the I-shaped steel blocks and thenmoving the base 205 downward. Therefore, the breaker unit 13 can bereplaced in a short time in the event of a failure. Further, since theI-shaped steel blocks can be attached at the site, the height of the gasinsulation switchgear during transportation is not increased. Althoughthe embodiment is described in the case of employing the I-shaped steelblocks, it is possible to use any members capable of being jacked downinstead of the I-shaped steel blocks.

[0068]FIG. 8 is another embodiment of a gas insulation switchgear usedfor a transmission line of which the portion from the main buses 4 a, 4b to the isolator unit 11 in the line side is constructed similar to theembodiment of FIG. 7. In the embodiment of FIG. 8, a cable head 40 isconnected to the isolator unit 11 in the line side through an insulationspacer 49. The cable head 40 is arranged in a level lower than theconductor. A vertical type arrester unit 9 is connected to the cablehead 40 through an insulation spacer 55. A voltage transformer unit 10is connected to the upper portion of the lightning arrester unit 9through an insulation spacer.

[0069] By constructing as described above, the two main buses and thetwo main isolator units can be horizontally arranged above the breakerunit 13 and the actuator 41, and the individual phase lines areconstructed from the three-phase single-unit main buses. Therefore, theouter diameter of the breaker unit can be made small and the outerdiameter of the main isolator unit can be also made small, andaccordingly the height of the gas insulation switchgear can be reduced.Further, the vertical type isolator in the line side is connected to thebreaker arranged in the lower level position, the levels of the voltagetransformer unit 10, the lightning arrester unit 9 and the cable headcan be also suppressed to a level equal to the level of the main busisolator unit. When the breaker unit 13 needs to be removed, the breakerunit 13 can be detached by moving the flange after discharging the gas.Therefore, the breaker unit 13 can be replaced in a short time in theevent of a failure.

[0070]FIG. 9 to FIG. 14 show the details of the main bus isolator unit15. The bus isolator unit portion 60 is formed in the bus connectingconductor 46 side of the main bus isolator unit 15, and the conductors63, 64 and 65 are arranged in the side opposite to the bus connectingconductor 46, and the mechanism portion 61 is arranged in the sideopposite to the bus isolator unit 60 with respect to these conductors.Insulation spacers 66 for fixing and supporting the conductors 63, 64,65 for three phases together are arranged in the both ends of a buscontainer 62. The conductors 63, 64, 65 are respectively arranged atvertexes of a triangle, and the conductors 63 and 64 are arranged in thebus connecting conductor 46 side and the conductor 65 is arranged in themechanism portion 61 side. It can be understood from comparing FIG. 8with FIG. 24 that even if connection of the buses becomes inverse, theconnection can not become difficult since the vertex direction of thetriangle is changed. Therein, although it is described that theconductors 63, 64, 65 are arranged in the triangular shape, theconductors may be arranged in a line.

[0071] The bus isolator unit 60 is formed of isolator containers 74separated individually to three phases in a direction perpendicular tothe axis line of the bus container 62 or branching portions of the buscontainer 62, and branched conductors of the conductors 63, 64, 65 areindividually arranged in the isolator containers 74. An insulationspacer 67 for fixing and supporting the branched conductor for one phaseis arranged in each of the isolator containers 74 to keep sealing of themain bus isolator unit 15. A fixed side conductor 68 is attached to theinsulation spacer 67 to form a fixed contact 69. The fixed sideconductor 68 is arranged in the center line portion of the isolatorcontainer 74. On the other hand, the mechanism portions 61 arerespectively arranged in mechanism portion containers 70, and a link 75of the mechanism portion 61 is connected to an actuator arranged outsidethe mechanism portion container 70. A movable contact is connected tothe link 75 through an insulation rod 71.

[0072] A movable side conductor 73 is arranged on the central axis ofthe isolator container 74 and opposite to the fixed side conductor 68.As shown in FIG. 12 to FIG. 14, the conductors 63, 64, 65 arerespectively connected to the movable side conductors 73 by branchconductors. A through hole is formed in the central portion of themovable side conductor 73. As shown in FIG. 10, the conductor 65 hasthrough holes for three phases formed at positions corresponding to thethrough holes formed in the movable side conductor 73, and the portionsof the through holes being formed have locally thick portions 76 inorder to secure current conduction capacity. As described above, each ofthe movable conductors 73 connected to the conductor 63 or 64 is formedso as to come to the center line portion of the isolator container 70 bythe locally thick portion 76, and the insulation rod 71 for driving themovable contact 72 to electrically connect or disconnect the conductor63 or 64 with or from the fixed side conductor 68 is formed so as to bemoved through the through hole formed in the conductor 65 which is forthe other phase. The insulation rod 71 for driving the movable contact72 to electrically connect or disconnect the conductor 65 with or fromthe fixed side conductor 68 is formed so as to be moved through thethrough hole formed in the conductor 65. Further, the insulation rod 71and the movable contacts 72 connected to the insulation rod 71 are movedthrough the through hole formed in the movable side conductor 73, andthe movable side conductor 73 can be electrically connected to anddisconnected from the fixed contact 69.

[0073] By constructing as described above, the insulation rods drivingthe movable contacts electrically connecting and disconnecting theconductors for two phases to and from the fixed side conductors areconstructed so as to be moved through the through holes formed in theconductor for the other phase. Therefore, the operating mechanismportions can be arranged in the side opposite to the bus isolation unitportion 60 with respect to the conductors 63 to 65. Further, the links75 for three phases can be horizontally arranged in nearly an equallevel, and the operating mechanism can be made simple in structure.Further, since the through holes for three phases are formed in theconductor in the mechanism portion side, it is possible to increasefreedom in that the movable contacts can be formed large in size, andthat the movable side conductors can be formed large in size.

[0074] The driving mechanism of the link 75 attached to the insulationrod 71 will be described below in detail, referring to FIG. 16 to FIG.19. A mechanism portion container 80 containing the link 75 is arrangedin the side opposite to the main bus insulator of the bus container 62.As shown in FIG. 16, FIG. 17 and FIG. 18, a cylindrical containerportion 81 is attached to the bus container 62 with welding or the like,and a flange 82 is attached to the cylindrical container portion 81. Aflange 83 is arranged in the mechanism portion container 80, and themechanism portion container 80 is attached to the bus container 62 byfixing the flanges 82, 83 with bolts through a sealant. The mechanismportion container 80 is formed in a rectangular or an elliptical crosssection, and the link 75 and the insulation rod are arranged in thelonger portion of the cross section. The insulation rod 71 and the link75 are rotatably connected to a connecting portion 87. A curvilinearhole is formed in the connection portion of the link 75, and theconnection portion of the insulation rod 71 is moved inside the hole tomove the insulation rod 71 straight. A hole 85 to be inserted with anaxis 84 is formed in the link 75, the axis 84 is arranged penetratingthrough the holes 85 for three phases.

[0075] Clamps 85, 86 having a sealant are attached outside the mechanismportion container 80 with bolts to seal and rotationally support theaxis 84. An inspection window 88 is formed at a position correspondingto the connecting portion 87 of the mechanism portion container 80, anda sealing plate 89 is fixed to the inspection window 88 with boltsthrough a sealant. As shown in FIG. 15, the actuators 42, 43 areattached to one ends of the axis 84 attached to the main isolator units4 a, 4 b, respectively, and the actuators 42, 43 are arranged in thesame direction in the embodiment shown in FIG. 15.

[0076] The mechanism portion of the grounding device 52 is alsoconstructed similarly to the mechanism portion of the main isolator unitdescribed above. As shown in FIG. 7 and FIG. 8, a flange is arranged inthe container of the upper portion of the bus connecting conductor 46,and this flange is connected to a flange arranged in the mechanismportion container 90 of the grounding device 52 with bolts through asealant. Although the mechanism portion container 90 is constructedsimilar to the mechanism portion container 80, the actuator is arrangedat a position opposite to the actuators 42, 43.

[0077] The links 75 for three phases can be connected with the singleaxis formed in a unit or formed by connecting rods together because thelinks are horizontally arranged in the nearly equal level as describedabove. Further, adjusting work of connecting the links for three phasescan be saved because the link mechanisms for three phases are connectedwith the single axis.

[0078] The current transformer unit 12 is constructed as follows. Acurrent transformer shown in FIG. 19 is an external mount type, and acurrent transformer shown in FIG. 20 is an internal mount type. Althoughthe current transformer of the external mount type is shown in FIG. 7and FIG. 8, the current transformer of the internal mount type may beemployed.

[0079] The current transformer unit 12 is composed of a currenttransformer case 101, a current transformer 100 and an insulation plate102 arranged between an insulation spacer 48 in the outer peripheralside of the conductor 103 connected by the tulip contact 104 and aflange portion 108 of the container. The current transformer unit 12 isformed in a unit different from the breaker unit 13. By forming thecurrent transformer unit 12 in the different unit, the isolator unit 11can be directly connected to the breaker unit when the currenttransformer unit can be omitted. Further, the current transformer unit12 can be easily replaced in the event of failure. A protective cover105 is arranged in the outer periphery of the current transformer case101. The current transformer 100 is fixed by a clamp arranged in theinsulation plate 102, and the shape is formed so as to be large in theouter diameter and small in the width.

[0080] Since the current transformer unit 102 is formed as describedabove, the length of the transformer unit can be shortened and the leadwire can be extracted to the outside through the protective cover.

[0081] The current transformer unit of the internal mount type iscomposed of a current transformer case 106 arranged in the outerperipheral side of the conductor between an insulation spacer 48 and aflange 108, a current transformer 100 arranged in the inner peripheralside of the current transformer case 106, and a clamp 109 for fixing thecurrent transformer 100 arranged in the current transformer case 106. Ahermetic seal terminal port 107 is arranged in the current transformercase 106 to extract the lead wire of the current transformer 100. Thecurrent transformer 100 is formed so as to be small in the outerdiameter and large in the width.

[0082] Since the current transformer unit is formed as described above,the outer diameter of the current transformer unit can be made smallthough the length is not short. Therefore, the bolts can be easilyscrewed when the current transformer unit is mounted. Further, number ofthe parts can be reduced.

[0083] Although the current transformer unit 12 has been describedabove, the current transformer unit 14 is connected to the containerinstead of the insulation spacer 48. Further, the current transformerunit 12 may be formed together with the breaker unit 13 in a unit.

[0084] The structure of the isolator unit 11 will be described below inmore detail, referring to FIG. 21 to FIG. 23. Cylindrical containers 112and 111 are arranged in the upper portion and the lower portion of theisolator unit 11 in a direction perpendicular to the axis line of theisolator container 110. One side of the container 111 is connected tothe insulation spacer 48 of the current transformer unit 12, and theother side is connected to the mechanism portion container 114 of thegrounding device 44 through a flange. One side of the container 112 isconnected to the mechanism portion container 115 of the grounding device45 through a flange, and the other side is connected to the insulationspacer 49 through a flange. The upper portion of the isolator container110 is connected to the mechanism portion container 116 of the isolator.

[0085] A fixed electrode 118 of the grounding device 44 is arranged in aconductor 117 fixed to and supported by the insulation spacer 48 in adirection of the axis line, and a fixed electrode 121 of the isolator isarranged in a direction of the axis line of the isolator container 110.A grounding bar 120 fixed by a hermetic seal terminal is attached to themechanism portion container 114, and formed so as to be in contact witha movable electrode 119. The grounding bar 120 is grounded. The movableelectrode 119 and the fixed electrode 118 are opened during normaloperation, and the movable electrode 119 is brought in contact with thefixed electrode 118 to ground by operation of the actuator connected tothe movable electrode 119 through a link 126 at inspection or the like.

[0086] A movable current collector is arranged in the fixed electrode121 side in a conductor portion 130 fixed to and supported by theinsulation spacer 49 attached to the container 112, and a fixedelectrode 123 of the grounding device 45 is arranged in the sideopposite to the insulation spacer 49 in the direction of the axis lineof the container 112. As shown in FIG. 22 and FIG. 23, a grounding bar131 is attached to the upper portion of the conductor portion 130through an insulator. A through hole is formed in the conductor portion130 so that a movable electrode 122 of the isolator connected to thegrounding bar through the insulation rod is reciprocally moved. A link128 is connected to the insulation rod with a connecting portion 129.

[0087] A grounding bar 125 sealed by a hermetic seal terminal isattached to the mechanism portion container 115, and constructed so asto be in contact with a movable electrode 124. The grounding bar 125 isgrounded. The movable electrode 124 and the fixed electrode 123 areopened during normal operation, and the movable electrode 124 is broughtin contact with the fixed electrode 123 to ground by operation of theactuator connected to the movable electrode 124 through a link 127 inthe event of failure or the like. The operating mechanism portionconnected to the link is constructed as follows. Although FIG. 22 andFIG. 23 show the case where the operating mechanism portion is attachedto the mechanism portion container of the isolator, the groundingdevices 44, 45 are also constructed similarly.

[0088] A flange is arranged in the mechanism container 116, and themechanism portion container 116 is attached to the isolator container110 by fixing the flanges together with bolts through a sealant. Themechanism portion container 116 is formed in a rectangular crosssection, and the link 128 and the insulation rod are arranged in thelonger side portion. The insulation rod and the link 128 are rotatablyconnected each other with a connecting portion 129. A hole to beinserted with an axis 132 is formed in the link 128, and the axis 132 isattached by penetrating through the holes of the links 128 for threephases. Conductors for three phases are arranged in parallel to oneanother inside the container, and one of the conductors for three phasesis arranged on the center line of the container. Each of the operatingaxes for three phases of the isolators is arranged on the center axis ofthe container in a direction perpendicular to these conductors for threephases, and the electrode gaps are arranged at one ends and theoperating mechanism portions are arranged at the other ends interposingthe conductors disposed on the center lines of the containers.

[0089] Since the grounding device is horizontally arranged on thehorizontally extending line of the breaker unit and above the currenttransformer unit, the space can be effectively used and the isolatorscan be also arranged.

[0090] Clamps 133, 134 having a sealant are attached to the outer sideof the mechanism portion container 116 to seal and rorarably support theaxis 132. An inspection window is arranged at a position correspondingto the connecting portion of the mechanism portion container 116, and aseal plate is fixed to the mechanism portion container 116 with boltsthrough a sealant. The actuator is attached to one end of the axis 132.

[0091] The construction of the gas insulation switchgear used for a buscommunication line will be described below in more detail, referring toFIG. 24. As shown in FIG. 24, a breaker unit 13 is horizontally placedin the lower side, and an actuator 41 for driving an movable contact ofthe breaker unit 13 is arranged in the left hand side of the breakerunit 13. A bus connecting conductor 140 is arranged above the breakerunit 13 through a current transformer unit 14 and a flange. The busconnecting conductor 140 and a conductor connected to the breaker unit13 are electrically connected with each other by a tulip contact portion207. There is no insulation spacer in the connecting portion of thebreaker unit 13, the current transformer 14 and the bus connectingconductor 140. The bus connecting conductor 140 is fixed to andsupported by insulation spacer 47 b, and the grounding device 52 isconnected to the upper portion of the bus connecting conductor 140through a flange. A main bus isolator 15 b is connected to theinsulation spacer 47 b, and an actuator 43 for operating a movablecontact provided in the main bus isolator unit 15 b is arranged outsidethe main bus isolator unit 15 b. A detachable support column 208 isarranged between the main bus isolator unit 15 b and the breaker unit13. Therefore, when the breaker unit 13 is removed, the main bus 4 b andthe main bus isolator unit 15 b can be supported by replacing thesupport column 208 with a column long enough to support them from theinstallation surface. As described above, since the insulation spacer 47b can be vertically arranged, accumulation of metallic extraneousobjects in the surface of the insulation spacer 47 b can be prevented,and accordingly the reliability of the insulation can be improved.

[0092] A conductor connecting unit 151 is arranged in the right handside of the breaker unit 13 through an insulation spacer 153, and agrounding device 152 is arranged on the extending line of the breakerunit 13. The conductor connecting unit 151 is constructed in a verticaltype, and the upper portion is connected to the main bus isolator unit153 through an insulation spacer 154 to be connected to the main bus 4a. The connecting ports have the same structure in the main buses 4 a, 4b. Therefore, the dimension e between the lines of the buses can beshortened. A tulip contact 210 is arranged in the conductor connectionunit 151. A flange is arranged in the container portion of the outerperipheral portion of the tulip contact 210 so as to divide theconductor connecting unit 151. A detachable support column 209 isarranged in the main bus 4 a. Therefore, when the breaker unit 13 isremoved, the main bus 4 a and the conductor connecting unit 151 can besupported by replacing the support column 151 with a column long enoughto support them from the installation surface.

[0093] The breaker unit 13 and the conductor connecting unit 151 aremounted on the base 211. I-shape steel blocks, not shown, are arrangedunder the base 211, and the base 211 is supported by the I-shaped steelblocks. The I-shaped steel block has a height of 250 mm. As describedabove, the bus connecting conductor 140 and the conductor 140 a areelectrically connected to each other with tulip contact, and the flange212 is arranged in the conductor connecting unit 151. Therefore, thebreaker unit 13 and the breaker unit 13 side of the conductor connectingunit 151 can be detached off from each other by removing the flangeafter discharging the gas. Accordingly, when the breaker unit 13 needsto be removed, the breaker unit 13 can be detached by once jacking upthe base 211 to remove the I-shaped steel blocks and then moving thebase 211 downward. Therefore, the breaker unit 13 can be replaced in ashort time in the event of a failure.

[0094] As described above, since the main bus isolator units 15 a, 15 bcan be arranged in a nearly equal level, the height of the gasinsulation switchgear can be reduced. Since in the gas insulationswitchgear in accordance with the present invention the individual phaselines are constructed from the three-phase single-unit main buses 4 a, 4b, the outer diameter of the breaker unit per phase can be made smalland the outer diameter of the main bus isolator units can be also madesmall. Therefore, the height of the gas insulation switchgear can belowered. For example, the height of a gas insulation switchgear of even300 kV class can be lowered to below 2 m 70 cm, and accordingly the gasinsulation switchgear can be transported by a trailer in a unit.Therefore, the transportation cost can be reduced. Further, theworkability can be improved because of easiness of inspection.Furthermore, since the breaker unit and the two main buses above theactuator and the main bus isolator unit can be horizontally arranged,the height of the gas insulation switchgear can be reduced.

[0095] As shown in FIG. 25, the gas insulation switchgear used for atransformer line is constructed similarly to the gas insulationswitchgear shown in FIG. 7 from the main buses 4 a, 4 b to the currenttransformer unit 12. A grounding device unit 156 is connected to thecurrent transformer unit 12 through an insulation spacer 48. A conductor159 fixed to and supported by the insulation spacers 48 and 157 isarranged in the lower side of the grounding device unit 156, and a fixedelectrode of the grounding device is arranged in the conductor 159. Theconductor 159 is connected to a conductor 54 through the insulationspacer 157, and the container containing the conductor 54 isgas-sectioned with the insulation spacers 157, 158 and 51. A lightningarrester 9 of a vertical type is connected to the upper portion of theinsulation spacer 51.

[0096] The bus connecting conductor 46 and the conductor connected tothe breaker unit 13 are electrically connected to each other with atulip contact portion 213. There is no insulation spacer in theconnection portions of the breaker unit 13, the current transformer unit14 and the bus connecting conductor 46. A tulip contact 214 is arrangedin the conductor 54. The conductor 54 can be detached by the insulationspacer 51.

[0097] Detachable support columns 215, 216 are arranged in the main bus4 a and the main bus isolator unit 15 b, respectively. Therefore, whenthe breaker unit 13 is removed, the main buses 4 a, 4 b and the main busisolator units 15 a, 15 b can be supported by replacing the supportcolumns 215, 216 with columns long enough to support them from theinstallation surface.

[0098] The breaker unit 13 and the conductor 159 and the conductor 54are mounted on the base 217. I-shape steel blocks, not shown, arearranged under the base 217, and the base 217 is supported by theI-shaped steel blocks. The I-shaped steel block has a height of 250 mm.As described above, the bus connecting conductor 46 and the conductor 46a are electrically connected to each other with tulip contact, and theinsulation spacer 51 is arranged in the conductor 54. Therefore, thebreaker unit 13 and the conductors 159 and 54 can be detached off fromeach other by removing the flange after discharging the gas.Accordingly, when the breaker unit 13 needs to be removed, the breakerunit 13 can be detached by once jacking up the base 217 to remove theI-shaped steel blocks and then moving the base 217 downward. Therefore,the breaker unit 13 can be replaced in a short time in the event of afailure.

[0099] As described above, the main bus isolator units are horizontallyarranged in parallel to each other without stacking in the verticaldirection to reduce the height of the gas insulation switchgear.Further, since the insulation spacers 47 a, 47 b can be verticallyarranged, accumulation of metallic extraneous objects in the surfaces ofthe insulation spacers 47 a, 47 b can be prevented, and accordingly thereliability of the insulation can be improved.

[0100] According to the gas insulation switchgear of the presentembodiment, as described above, since the main bus isolator units 15 a,15 b having the mechanism portion arranged horizontally can be connectedto the both sides of the bus container containing the bus connectingconductor 46, the height of the gas insulation switchgear can bereduced. Particularly, the height of a gas insulation switchgear of even300 kV class can be lowered to below 2 m 70 cm, and accordingly the gasinsulation switchgear can be transported by a trailer in a unit.Further, when the isolator is horizontally arranged in the conventionalstructure of the movable contact of the isolator, the insulation spacermust be arranged horizontally. Therefore, there is a problem in thatmetallic extraneous objects are accumulated on the insulation spacer andthe insulating performance is deteriorated to decrease the reliability.However, according to the gas insulation switchgear of the presentembodiment, since the insulation spacers can be vertically arranged evenwhen the isolator unit is horizontally arranged, the insulatingperformance can be improved. Further, in the conventional gas insulationswitchgear, the heights of the transmission line, the bus communicationline, the bus section line and the transformer line are different fromone another. However, in the gas insulation switchgear of the presentembodiment, the heights of the transmission line, the bus communicationline, the bus section line and the transformer line can be nearly equalto one another, and each of the transmission line, the bus communicationline, the bus section line and the transformer line can be transportedin a unit.

[0101] Further, since the main bus isolator units 15 a, 15 b arehorizontally arranged in the upper portion, workability of theinstallation work and inspection work can be improved. Furthermore,since the heavy weight breaker can be arranged in the lower position,the seismic resistance can be improved.

[0102] In the gas insulation switchgear of the present embodiment, thelengths of the transmission line, the bus communication line, the bussection line and the transformer line can be shortened including thevoltage transformer unit and so on because the two main bus and the mainbus isolator unit are arranged above the breaker unit and the actuator.Since the length of the bus communication line can be shortened, theposition connecting the bus to the transformer can be placed near thegas insulation switchgear.

[0103] Further, the bus communication line and the bus section line canbe made similar to each other in construction, and the transmission lineand the transformer line can be also made similar to each other inconstruction. Therefore, the commonality of system construction can beattained. In addition, since the distance between the two lines of themain buses 4 a and the distance between the two lines of the buses 4 bcan be decreased, the total length of the system can be shortened. As aresult, the gas insulation switchgear of a high voltage of 300 kV can beinstalled within an area of about 13 m width and about 30 m length.

[0104] Furthermore, since the buses from the bushings and the busesconnecting to the transformer can be arranged in the low-level position,the installation work can be easily performed and the seismic resistancecan be improved.

[0105] Another embodiment of the present invention will be describedbelow, referring to FIG. 26. FIG. 26 is a front view showing a gasinsulation switchgear used for a transmission line. Although the gasinsulation switchgear of the present embodiment is constructed similarlyto the embodiment shown in FIG. 7, in the present embodiment theconductors 63, 64, 65 of the main buses 4 a, 4 b are vertically orhorizontally aligned in a line. A grounding device 52 is arranged ineither of the main bus 4 a or the main bus 4 b, and there is nogrounding device in the bus connecting conductor 46. An insulationspacer 47 c horizontally is arranged in a flange connecting portionbetween the breaker unit 13 containing the breaker portion inside anintegrated tank and the current transformer 14. The current transformer12 is connected to the isolator unit 11 a through a bellows 220. Theisolator unit 11 a employed is of a vertical type, and grounding devices221 and 223 are arranged in the lower portion and the upper portion andan isolator 222 is arranged in the middle portion. The isolator unit 11a is constructed similarly to the construction described in FIG. 9 toFIG. 14. The grounding device 223 arranged in the upper portion isconnected to a lightning arrester unit 9 through an insulation spacer224.

[0106] By constructing as described above, the two main buses and themain bus isolator units can be horizontally arranged above the breakerunit 13 and the actuator 41, and the individual phase lines areconstructed from the three-phase single-unit main buses. Therefore, theouter diameter of the breaker unit can be made small, and the outerdiameter of the main bus isolator unit can be made small, and the heightof the gas insulation switchgear can be reduced. In this case, theinsulation spacer may be -horizontally arranged, and accordingly thesection of the breaker unit 13 can be made small and it becomesadvantageous in the aspect of protection and monitoring. Further, theinsulation rods driving the movable contacts electrically connecting anddisconnecting the conductors for two phases to and from the fixed sideconductors are constructed so as to be moved through the through holesformed in the conductor for the other phase. Therefore, the operatingmechanism portions can be arranged in the side opposite to the busisolation unit portion with respect to the conductors 63 to 65. Further,the links for three phases can be horizontally arranged in nearly anequal level, and the operating mechanism can be made simple instructure. Further, since the through holes for three phases are formedin the conductor in the mechanism portion side, it is possible toincrease freedom in that the movable contacts can be formed large insize, and that the movable side conductors can be formed large in size.

[0107] Another embodiment of the present invention will be describedbelow, referring to FIG. 27 and FIG. 28. Each of FIG. 27 and FIG. 28 isa vertical cross-sectional view showing the structure of a gasinsulation switchgear in which the main buses are arranged in the lowerposition.

[0108] In the embodiment shown in FIG. 27, the main bus isolator units15 a, 15 b shown in FIG. 9 to FIG. 14 are connected to the three-phasesingle-unit main bus 4 a and the three-phase single-unit main bus 4 b.Operating mechanism containers 70 are arranged in the lower position,and insulation spacers 47 d, 47 e are attached to flange connectingportions with bus connecting conductors 46 a, 46 b. A grounding device52 a is arranged in an end portion of the bus connecting conductor 46 a.the bus connecting conductor 46 a and the bus connecting conductor 46 bare connected to each other through a bellows 225 a and an insulationspacer 226, and the bus connecting conductor 225 b is connected to acurrent transformer unit, not shown, through a bellows 225 b. Anisolator unit 11 a used is of a vertical type, and the isolator unit 11a is constructed similarly to the construction described in FIG. 9 toFIG. 14.

[0109] Although the embodiment of FIG. 28 is constructed similarly tothe embodiment of FIG. 27, in the embodiment of FIG. 28 a bus connectionconductor 46 c having a bellows 227 is interposed between the busconnection conductor 46 a and the bus connection conductor 46 b, and thebus connecting conductor 46 a is connected to the bus connectingconductor 46 c through an insulation spacer 228, and the bus connectingconductor 46 c is connected to the bus connecting conductor 46 b throughan insulation spacer 229.

[0110] By constructing as described above, the insulation rods drivingthe movable contacts electrically connecting and disconnecting theconductors for two phases to and from the fixed side conductors areconstructed so as to be moved through the through holes formed in theconductor for the other phase. Therefore, the operating mechanismportions can be arranged in the same side opposite to the bus isolationunit portion with respect to the conductors 63 to 65. Further, the linksfor three phases can be horizontally arranged in nearly an equal level,and the operating mechanism can be made simple in structure. Further,since the through holes for three phases are formed in the conductor inthe mechanism portion side, it is possible to increase freedom in thatthe movable contacts can be formed large in size, and that the movableside conductors can be formed large in size.

INDUSTRIAL APPLICATION

[0111] According to the present invention, since the individual phaselines are constructed from the three-phase single-unit main buses 4 a, 4b, the outer diameter of the breaker unit can be made small, and theouter diameter of the main bus isolator unit can be made small, and theheight of the gas insulation switchgear can be reduced.

[0112] Further, since the main bus isolator units can be connected tothe both sides of the bus container, the height of the gas insulationswitchgear can be lowered.

[0113] Further, since the insulation spacer is not horizontally arrangedeven if the breaker unit is horizontally arranged, the reliability ofinsulation can be improved.

What is claimed is:
 1. A gas insulation switchgear comprising: a breakerunit horizontally arranged and containing a conductor for one phase in acontainer; a bus side connecting conductor vertically arranged andconnected to said breaker; three-phase single-unit type main bus unitsarranged in both sides of said bus side connecting conductor and in anaxial direction of said breaker unit; and a line side connectingconductor connected to said breaker unit.
 2. A gas insulation switchgearfor bus communication line comprising: a breaker unit horizontallyarranged and containing a conductor for one phase in a container; a busside connecting conductor vertically arranged and connected to saidbreaker; a three-phase single-unit type main bus A connected to said busside connecting conductor; a line side connecting conductor connected tosaid breaker unit; and a three-phase single-unit type main bus Bconnected to said line side connecting conductor, wherein a connectingport to the main bus A of said bus side connecting conductor and aconnecting port to the main bus B of said line side connecting conductorare arranged in the same direction.
 3. A gas insulation switchgearcomprising: a breaker unit having a bus section line and a buscommunication line horizontally arranged, containing a conductor for onephase in a container; a bus side connecting conductor verticallyarranged and connected to said breaker; three-phase single-unit typemain bus units arranged in both sides of said bus side connectingconductor and in an axial direction of said breaker unit; and a lineside connecting conductor connected to said breaker units.
 4. In asubstation comprising a transmission line, a bus communication line, abus section line and a transformer line, a gas insulation switchgearhaving a voltage transformer unit in said bus section line.
 5. A gasinsulation switchgear comprising: a breaker unit having a bus sectionline horizontally arranged, containing a conductor for one phase in acontainer; a bus side connecting conductor vertically arranged andconnected to said breaker; three-phase single-unit type main bus unitsarranged in both sides of said bus side connecting conductor and in anaxial direction of said breaker unit; a line side connecting conductorconnected to said breaker units; and a voltage transformer connected toan end portion of said main bus.
 6. A gas insulation switchgearaccording to claim 1, wherein said line side conductor has an isolatorunit, and said breaker unit and said isolator unit are mounted on abase, and a portion between the breaker unit and the bus side connectingconductor and a portion between the breaker unit and the isolator unitare so constructed as to be separable.
 7. A gas insulation switchgearaccording to claim 6, wherein a second base is arranged below said base.8. A method of installing a gas insulation switchgear, the gasinsulation switchgear comprising a breaker unit horizontally arrangedand containing a conductor for one phase in a container; a bus sideconnecting conductor vertically arranged and connected to said breaker;three-phase single-unit type main bus units arranged in both sides ofsaid bus side connecting conductor and in an axial direction of saidbreaker unit; and a line side connecting conductor connected to saidbreaker unit, said breaker unit and said isolator unit being mounted ona base, a portion between the breaker unit and the bus side connectingconductor and a portion between the breaker unit and the line sideconnecting conductor being so constructed as to be separable, whereinsaid gas insulation switchgear is transported as a unit when said gasinsulation switchgear is transported, and said gas insulation switchgearis mounted on a second base.
 9. A method of installing a gas insulationswitchgear according to claim 8, wherein when said breaker unit isdisassembled, said breaker unit is dismounted by supporting said mainbus unit with the other support column, and detaching the portionbetween the breaker unit and the bus side connecting conductor and theportion between the breaker unit and the line side connecting conductorafter removing said second base.
 10. A gas insulation switchgearcomprising: a breaker unit horizontally arranged; a bus side connectingconductor vertically arranged and connected to said breaker; a currenttransformer unit arranged below said bus side connecting conductor;three-phase single-unit type main bus units arranged in both sides ofsaid bus side connecting conductor and in an axial direction of saidbreaker unit; and a line side connecting conductor connected to saidbreaker unit.
 11. A gas insulation switchgear according to any one ofclaim 1 and claim 2, wherein a current transformer unit is connected tosaid breaker unit, and said breaker unit, said bus side connectingconductor and said current transformer are so constructed as to have acommon gas section.
 12. A gas insulation switchgear according to any oneof claim 1 and claim 2, wherein a current transformer unit is connectedto said breaker unit, and said current transformer is so constructed tohave a tank different from a tank of the breaker unit.
 13. A gasinsulation switchgear comprising: a breaker unit horizontally arranged;a bus side connecting conductor vertically arranged and connected tosaid breaker; three-phase single-unit type main bus units arranged inboth sides of said bus side connecting conductor and in an axialdirection of said breaker unit; and a line side connecting conductorconnected to said breaker unit, wherein said line side connectingconductor is connected to a line side component through a currenttransformer arranged vertically and an extendable joint.
 14. A gasinsulation switchgear according to claim 13, wherein said mainconductors for three phases are horizontally or vertically arranged in arow.
 15. A gas insulation switchgear comprising: a breaker unithorizontally arranged; a bus side connecting conductor verticallyarranged and connected to said breaker; three-phase single-unit typemain bus units arranged in both sides of said bus side connectingconductor and in an axial direction of said breaker unit; and a lineside connecting conductor connected to said breaker unit, wherein aninsulation spacer is horizontally arranged between said line sideconnecting conductor and said breaker unit, and a grounding device isarranged in said main bus unit.
 16. A gas insulation switchgearcomprising: a breaker unit horizontally arranged; a bus side connectingconductor vertically arranged and connected to said breaker; three-phasesingle-unit type main bus units arranged in both sides of said bus sideconnecting conductor and in an axial direction of said breaker unit; anda line side connecting conductor connected to said breaker unit, whereinsaid line side connecting conductor is connected to a breaker sidegrounding device, an isolator and a line side isolator which arecontained in a container vertically arranged.